FileAPI: Add WebFileSystem::resolveURL

public/platform/WebFileSystem.h

Index: public/platform/WebFileSystem.h
diff --git a/public/platform/WebFileSystem.h b/public/platform/WebFileSystem.h
index d2283d03bba673eae5f9fc3d7434271acd93f7d8..47e7a3346c838eaf08e2b902ecb64247e76f384d 100644
--- a/public/platform/WebFileSystem.h
+++ b/public/platform/WebFileSystem.h
@@ -66,6 +66,9 @@ public:
     // create root path for file systems if it do not exist.
     virtual void openFileSystem(const WebURL& storagePartition, const WebFileSystemType, bool create, WebFileSystemCallbacks*) { WEBKIT_ASSERT_NOT_REACHED(); }
 
+    // TODO(nhiroki): writing comment.
+    virtual void resolveURL(const WebURL& completedURL, WebFileSystemCallbacks*) { WEBKIT_ASSERT_NOT_REACHED(); }
+
     // Deletes FileSystem.
     // WebFileSystemCallbacks::didSucceed() must be called when the operation
     // is completed successfully. WebFileSystemCallbacks::didFail() must be